This invention relates to the protection of structures from excessive heating, and, more particularly, to an attachable insulative panel and its applications.
The structure of manned aircraft and helicopters, unmanned missiles, and spacecraft (collectively termed "aircraft" herein) may be heated to high temperatures during flight. The heating is typically a result of one of two causes, aerodynamic heating caused by the friction of air against the structure during flight through the atmosphere, and propulsive heating caused by the hot gases produced within a gas turbine or rocket engine. Either type of heating reduces the strength of the structure, and may lead to long-term degradation of the structure. Additionally, externally visible structure that is hot is detectable on infrared detectors.
There have been many techniques applied to reduce the effects of heat on a structure. The present invention relates to one such approach, the placement of insulative barriers between the heat source and the structure to be protected. Such barriers generally function in the same manner as conventional insulation, creating a thermal gradient between the high external temperature and the underlying structure. As a result of the thermal gradient, the underlying structure remains cooler than it would be if exposed directly to the external heating, and therefore suffers less degradation than would otherwise be the case.
There are several types of thermal barrier approaches. One is a thermal barrier coating (or "TBC") system. A thermal barrier coating is a ceramic material that is deposited as an overlayer on a structural substrate to be protected. In most instances, a bond coat layer is deposited on the substrate first, to improve the adhesion of the thermal barrier coating, which is then applied over the bond coat.
Although thermal barrier coatings are operable and work well in many applications, they have shortcomings when used in other applications. Even with the bond coat, there is a tendency for the ceramic thermal barrier coating to separate from the structure during repeated thermal cycling. Another problem is integration of the thermal barrier coating system with particular substrate applications, which may be difficult due to the configuration of the substrate or other reasons.
Thus, there is a need for an improved thermal insulative system. The present invention fulfills this need, and further provides related advantages.